Figure 2: Effect of hypoxia and reoxygenation on cardiomyocytes viability. Isolated myocardial cells were subjected to hypoxia throughout the experimental period (closed circle) or reoxygenated after 120-min exposure to hypoxia (open circle) in respiratory chambers. At indicated time points, aliquot of cells was removed for determination of viability by observing whether the cells could exclude trypan blue dye in a hypotonic (85 mOsmol) solution. Those cells unable to exclude the dye are considered to have undergone membrane failure and are, therefore, deemed nonviable. Each point represents mean ± standard error of six determinations